A Fibonacci number is a member of the Fibonacci sequence, a series of numbers where each number is the sum of the two preceding ones, usually starting with 0 and 1. The sequence begins:
Starting with 0 and 1, each subsequent Fibonacci number is obtained by adding the two numbers that precede it. Mathematically, it can be defined by the recurrence relation:
with initial conditions and .
The Fibonacci sequence has many interesting mathematical properties and applications, and it often appears in various areas of mathematics and nature, including the arrangement of leaves on a stem, the branching of trees, and the arrangement of seeds in a sunflower.